Building control system using integrated MEMS devices

ABSTRACT

An apparatus for use in a building system includes at least one microelectromechanical (MEMS) sensor device and a processing circuit that are integrated onto a single substrate. The at least one MEMs sensor device is operable to generate a process value. The processing circuit is operable convert the process value to an output digital signal configured to be communicated to another element of a building automation system. The building automation system includes one or more devices that are operable to generate a control output based on set point information and process value information from one or more sensors.

[0001] This application is a Divisional of U.S. patent application Ser.No. 10/353,110, filed Jan. 28, 2003.

CROSS REFERENCE TO RELATED APPLICATION

[0002] Cross reference is made to U.S. patent application Ser.No.10/353,142, filed Jan. 28, 2003, and which is incorporated herein byreference.

FIELD OF THE INVENTION

[0003] The present invention relates generally to building controlsystems, such of the type that control heating, ventilation, airconditioning, fire safety, lighting, security and other systems of abuilding or facility.

BACKGROUND OF THE INVENTION

[0004] Building control systems are employed to regulate and controlvarious environmental and safety aspects of commercial, industrial andresidential facilities (hereinafter referred to as “buildings”). Inordinary single-family residences, control systems tend to be simple andlargely unintegrated. However, in large buildings, building controlsystems often consist of multiple, integrated subsystems employinghundreds of elements.

[0005] For example, a heating, ventilation and air-conditioning (“HVAC”)building control system interrelates small, local control loops withlarger control loops to coordinate the delivery of heat, vented air, andchilled air to various locations throughout a large building. Localcontrol systems may use local room temperature readings to open or closevents that supply heated or chilled air. Larger control loops may obtainmany temperature readings and/or air flow readings to control the speedof a ventilation fan, or control the operation of heating or chillingequipment.

[0006] To facilitate the control over various aspects of a building,control systems employ sensing devices that measure various conditions,such as temperature, air flow, or motion. Other sensors determine thepresence of smoke, the presence of dangerous or noxious chemicals, lightand the like. Sensor devices for use in building control systems canvary widely in function, size and cost. Many sensors include mechanical,electromechanical and electronic elements and thus include a significantamount of parts that must be manufactured and assembled. In many cases,a building will have sensor devices from multiple manufacturers thatprovide different types of output signals.

[0007] Thus, a significant cost of a building control system relates tothe use of sensor devices. Such costs include the complex and oftenbulky sensor units as well as the costs associated with incorporatingand converting various types of sensor signals to a format used by thebuilding control system.

[0008] As a consequence, there is a need for apparatus and method thatcan reduce at least some of the drawbacks and costs identified above.For example, there is a need for a method and/or apparatus that reducesthe costs associated with the sensing devices that are necessary forsensing conditions within a building control system. There is a furtherneed for a sensor that reduces the need for external signal conversionequipment.

SUMMARY OF THE INVENTION

[0009] The present invention addresses one or more of the above needs,as well as others, by providing a building control system thatincorporates sensor units that include at least onemicroelectromechanical (“MEMs”) sensor devices. By incorporating MEMssensors, the mechanical and/or electromechanical elements of the sensormay readily be incorporated with electronic elements such as processingdevices. In embodiments of the invention, the MEMs sensor devices and atleast parts of the electronic elements are integrated onto a singlesubstrate. The use of such sensors can result in reduced material cost,bulk and energy costs. The electronic elements may be used to convertraw sensor signals into sensor value signals understood by otherelements of the building control system, thereby reducing the need forseparate driver/conversion circuitry.

[0010] A first embodiment of the invention is an apparatus for use in abuilding system that includes at least one microelectromechanical (MEMs)sensor device and a processing circuit that are integrated onto a singlesubstrate. The at least one MEMs sensor device is operable to generate aprocess value. The processing circuit is operable convert the processvalue to an output digital signal configured to be communicated toanother element of a building automation system. The building automationsystem includes one or more devices that are operable to generate acontrol output based on set point information and process valueinformation from one or more sensors.

[0011] Other embodiments of the apparatus include additional circuitelements, such as an EEPROM, a A/D converter, and/or an RF communicationcircuit.

[0012] Another embodiment of the invention is an arrangement for use ina building system that includes a plurality of sensor modules and aplurality of controllers. Each of sensor modules includes at least oneMEMs sensor device. Each sensor module is operable to obtain at leastone value representative of a measurable quantity in a building. Eachcontroller is operably connected to receive sensor informationrepresentative of at least one value obtained by at least one MEMssensor device, each controller is configured to generate a controloutput based on the sensor information and set point information, thecontrol output configured to cause an actuator to effect change to themeasurable quantity.

[0013] The above described features and advantages, as well as others,will become more readily apparent to those of ordinary skill in the artby reference to the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows a block diagram of an exemplary building controlsystem in accordance with the present invention;

[0015]FIG. 2 shows a block diagram of an exemplary space controlsubsystem of the building control system of FIG. 1;

[0016]FIG. 3 shows a flow diagram of an exemplary set of operations of aroom control processor of the space control subsystem of FIG. 2;

[0017]FIG. 4 shows a flow diagram of an exemplary set of operations of asensor module controller of the space control subsystem of FIG. 2; and

[0018]FIG. 5 shows a flow diagram of an exemplary set of operations ofan actuator module controller of the space control subsystem of FIG. 2.

[0019]FIG. 6 shows a block diagram of a space control subsystem of thebuilding control system of FIG. 1 that includes a plurality of fumehoods in accordance with the invention;

[0020]FIG. 7a shows a block diagram of a control module of the spacecontrol subsystem of FIG. 6;

[0021]FIG. 7b shows a flow diagram of the operations of the processingcircuit of the control module of FIG. 7a;

[0022]FIG. 8a shows a block diagram of a supply module of the spacecontrol subsystem of FIG. 6;

[0023]FIG. 8b shows a first flow diagram of the operations of theprocessing circuit of the supply module of FIG. 8a;

[0024]FIG. 8c shows a second flow diagram of the operations of theprocessing circuit of the supply module of FIG. 8a;

[0025]FIG. 9a shows a block diagram of a main exhaust module of thespace control subsystem of FIG. 6;

[0026]FIG. 9b shows a flow diagram of the operations of the processingcircuit of the main exhaust module of FIG. 9a;

[0027]FIG. 10a shows a block diagram of a fume hood sensor module of thespace control subsystem of FIG. 6;

[0028]FIG. 10b shows a flow diagram of the operations of the processingcircuit of the fume hood sensor module of FIG. 10a;

[0029]FIG. 11a shows a block diagram of a fume hood exhaust module ofthe space control subsystem of FIG. 6;

[0030]FIG. 11b shows a flow diagram of the operations of the processingcircuit of the fume hood exhaust module of FIG. 11a;

[0031]FIG. 12a shows a representative side view of a control systemmodule according to an aspect of the invention; and

[0032]FIG. 12b shows a representative block diagram of the controlsystem module of FIG. 12a.

DETAILED DESCRIPTION

[0033]FIG. 1 shows a block diagram of an exemplary building controlsystem in accordance with the present invention. The building controlsystem 100 includes a supervisory computer 102, a wireless area networkserver 104, a chiller controller subsystem 106, a fan controllersubsystem 108, and room controller subsystems 110, 112 and 114. Thebuilding control system 100 includes only the few above-mentionedelements for clarity of exposition of the principles of the invention.Typical building control systems will include many more space controlsubsystems, as well as many more chiller, fan, heater, and otherbuilding HVAC subsystems. Those of ordinary skill in the art may readilyincorporate the methods and features of the invention described hereininto building control systems of larger scale.

[0034] In general, the building control system 100 employs a firstwireless communication scheme to effect communications between thesupervisory computer 102, the chiller controller subsystem 106, the fancontroller subsystem 108, and the room controller subsystems 110, 112and 114. A wireless communication scheme identifies the specificprotocols and RF frequency plan employed in wireless communicationsbetween sets of wireless devices. In the embodiment described herein,the first wireless communication scheme is implemented as a wirelessarea network. To this end, a wireless area network server 104 coupled tothe supervisory computer 102 employs a packet-hopping wireless protocolto effect communication by and among the various subsystems of thebuilding control system 100. U.S. Pat. No. 5,737,318, which isincorporated herein by reference, describes a wireless packet hoppingnetwork that is suitable for HVAC/building control systems ofsubstantial size.

[0035] In general, the chiller controller subsystem 106 is a subsystemthat is operable to control the operation of a chiller plant, not shown,within the building. Chiller plants, as is known in art, are systemsthat are capable of chilling air that may then be ventilated throughoutall or part of the building to enable air conditioning. Variousoperations of chiller plants depend upon a number of input values, as isknown in the art. Some of the input values may be generated within thechiller controller subsystem 106, and other input values are externallygenerated. For example, operation of the chiller plant may be adjustedbased on various air flow and/or temperature values generated throughoutthe building. The operation of the chiller plant may also be affected byset point values generated by the supervisory computer 102. Theexternally-generated values are communicated to the chiller controllersubsystem 106 using the wireless area network.

[0036] The fan controller subsystem 108 is a subsystem that is operableto control the operation of a ventilation fan, not shown, within thebuilding. A ventilation fan, as is known in art, is a prime mover of airflow throughout the ventilation system of the building. This primary airflow power may be used to refresh the air within the facility, and maybe used to distribute chilled air from the chiller plant. As with thechiller plant, ventilation fans and their implementation within buildingcontrol systems are well known in the art. Also, the fan controllersubsystem 108 is similarly configured to receive input values from othersubsystems (or the supervisory computer 102) over the wireless areanetwork.

[0037] The room controllers 110, 112 and 114 are local controllersubsystems that operate to control an environmental aspect of a locationor “space” within the building. While such locations may be referred toherein as “rooms” for convenience, it will be appreciated that suchlocations may further be defined zones within larger open or semi-openspaces of a building. The environmental aspect(s) that are controllableby the space control subsystems 110, 112 and 114 typically includetemperature, and may include air quality, lighting and other buildingsystem processes.

[0038] In accordance with one aspect of the present invention, each ofthe space control subsystems 110, 112 and 114 has multiple elements thatcommunicate with each other using a second wireless communicationscheme. In general, it is preferable that the second communicationscheme employ a short-range or local RF communication sheme such asBluetooth. FIG. 2, discussed further below, shows a schematic blockdiagram of an exemplary room control system that may be used as thespace control subsystems 110.

[0039] Referring to FIG. 2, the space control subsystem 110 includes ahub module 202, first and second sensor modules 204 and 206,respectively, and an actuator module 208. It will be appreciated that aparticular room controller subsystem 200 may contain more or less sensormodules or actuator modules. In the exemplary embodiment describedherein, the space control subsystem 110 is operable to assist inregulating the temperature within a room or space pursuant to a setpoint value. The space control subsystem 110 is further operable toobtain data regarding the general environment of the room for use,display or recording by a remote device, not shown in FIG. 2, of thebuilding control system. (E.g., supervisory computer 102 of FIG. 1).

[0040] The first sensor module 204 represents a temperature sensormodule and is preferably embodied as a wireless integrated networksensor that incorporates microelectromechanical system technology(“MEMS”). By way of example, in the exemplary embodiment describedherein, the first sensor module 204 includes a MEMS local RFcommunication circuit 210, a microcontroller 212, a programmablenon-volative memory 214, a signal processing circuit 216, and one ormore MEMS sensor devices 218. The first sensor module 204 also containsa power supply/source 220. In the preferred embodiment described herein,the power supply/source 220 is a battery, for example, a coin cellbattery.

[0041] Examples of MEMS circuits suitable for implementing the firstsensor module 204 are described in the ESSCIRC98 Presentation “WirelessIntegrated Network Sensors (WINS)”, which is published on-line atwww.janet.ucla.edu/WINS/archives, (hereinafter referred to as the “WINSPresentation”), and which is incorporated herein by reference.

[0042] The MEMS sensor device(s) 218 include at least one MEMS sensor,which may suitably be a temperature sensor, flow sensor, pressuresensor, and/or gas-specific sensor. MEMS devices capable of obtainingtemperature, flow, pressure and gas content readings have been developedand are known in the art. In a preferred embodiment, several sensors areincorporated into a single device as a sensor suite 218. Uponinstallation, the sensor module 204 may be programmed to enable theparticular sensing capability. By incorporating different, selectablesensor capabilities, a single sensor module design may be manufacturedfor use in a large majority of HVAC sensing applications. In theembodiment of FIG. 2, the sensor module 204 is configured to enable itstemperature sensing function.

[0043] The signal processing circuit 216 includes the circuitry thatinterfaces with the sensor, converts analog sensor signals to digitalsignals, and provides the digital signals to the microcontroller 212.Examples of low power, micro-electronic A/D converters and sensorinterface circuitry are shown in the WINS Presentation.

[0044] The programmable non-volatile memory 214, which may be embodiedas a flash programmable EEPROM, stores configuration information for thesensor module 204. By way of example, programmable non-volatile memory214 preferably includes system identification information, which is usedto associate the information generated by the sensor module 204 with itsphysical and/or logical location in the building control system. Forexample, the programmable non-volatile memory 214 may contain an“address” or “ID” of the sensor module 204 that is appended to anycommunications generated by the sensor module 110.

[0045] The memory 214 further includes set-up configuration informationrelated to the type of sensor being used. For example, if the sensordevice(s) 218 are implemented as a suite of sensor devices, the memory214 includes the information that identifies which sensor functionalityto enable. (See FIGS. 3 and 4, discussed further below). The memory 214may further include calibration information regarding the sensor, andsystem RF communication parameters (i.e. the second RF communicationscheme) employed by the microcontroller 212 and/or RF communicationcircuit 210 to transmit information to other devices.

[0046] The microcontroller 212 is a processing circuit operable tocontrol the general operation of the sensor module 204. In general,however, the microcontroller 212 receives digital sensor informationfrom the signal processing circuit 216 and provides the information tothe local RF communication circuit 210 for transmission to a localdevice, for example, the hub module 202. The microcontroller 212 maycause the transmission of sensor data from time-to-time as dictated byan internal counter or clock, or in response to a request received fromthe hub module 202.

[0047] The microcontroller 212 is further operable to receiveconfiguration information via the RF communication circuit 210, storeconfiguration information in the memory 214, and perform operations inaccordance with such configuration information. As discussed above, theconfiguration information may define which of multiple possible sensorfunctionalities is to be provided by the sensor module 204. Themicrocontroller 212 employs such information to cause the appropriatesensor device or devices from the sensor device suite 218 to be operablyconnected to the signal processing circuit such that sensed signals fromthe appropriate sensor device are digitized and provided to themicrocontroller 212. As discussed above, the microcontroller 212 mayalso use the configuration information to format outgoing messagesand/or control operation of the RF communication circuit 210.

[0048] The MEMS local RF communication circuit 210 may suitably includea Bluetooth RF modem, or some other type of short range (about 30-100feet) RF communication modem. The use of a MEMS-based RF communicationcircuit allows for reduced power consumption, thereby enabling thepotential use of a true wireless, battery operated sensor module 204. Asuitable exemplary MEMS-based RF communication circuit is discussed inthe WINS Presentation.

[0049] As discussed above, it is assumed that the sensor module 204 isconfigured to operate as a temperature sensor. To this end, the memory214 stores information identifying that the sensor module 204 is tooperate as a temperature sensor. Such information may be programmed intothe memory 214 via a wireless programmer. The module 204 may beprogrammed upon shipment from the factory, or upon installation into thebuilding control system. The microcontroller 212, responsive to theconfiguration information, causes the signal processing circuit 216 toprocess signals only from the temperature sensor, ignoring output fromother sensors of the sensor suite 218.

[0050] It will be appreciated that in other embodiments, the sensorsuite 218 may be replaced by a single sensor. However, additionaladvantages may be realized through the use of a configurable sensormodule capable of performing any of a plurality of sensor functions. Asdiscussed further above, these advantages include the reduction of thenumber of sensor module designs.

[0051] In addition, the reduced wiring requirements and the reducedpower consumption of the above described design provides benefits evenin non-battery operated sensors.

[0052] The sensor module 206 is configured to operate as a flow sensorin the embodiment described herein. The sensor module 206 may suitablyhave the same physical construction as the sensor module 204. To thisend, the sensor module 206 includes a local RF communication circuit230, a microcontroller 232, a programmable non-volatile memory 234, asignal processing circuit 236, a sensor suite 238, and a powersupply/source 240. In contrast to the sensor module 204, however, thememory 234 of the sensor module 206 contains configuration informationidentifying that the sensor module 206 is to function as a flow sensor.

[0053] The actuator module 208 is a device that is operable to causemovement or actuation of a physical device that has the ability tochange a parameter of the building environment. For example, theactuator module 208 in the embodiment described herein is operable tocontrol the position of a ventilation damper, thereby controlling theflow of heated or chilled air into the room.

[0054] The actuator module 208 is also preferably embodied as a wirelessintegrated network device that incorporates microelectromechanicalsystem (“MEMS”) devices. By way of example, in the exemplary embodimentdescribed herein, the actuator module 208 includes a MEMS local RFcommunication circuit 250, a microcontroller 252, a programmablenon-volatile memory 254, and a signal processing circuit 256. Theactuator module 208 also contains a power supply/source 260. In thepreferred embodiment described herein, the power supply/source 260 is abattery, for example, a coin cell battery. However, it will beappreciated that if AC power is necessary for the actuator device (i.e.the damper actuator), which may be solenoid or value, then AC power isreadily available for the power supply/source 260. As a consequence, theuse of battery power is not necessarily advantageous.

[0055] The actuator 262 itself may suitably be a solenoid, steppermotor, or other electrically controllable device that drives amechanical HVAC element. In the exemplary embodiment described herein,the actuator 262 is a stepper motor for controlling the position of avent damper.

[0056] The MEMS local RF communication circuit 250 may suitably be ofsimilar construction and operation as the MEMS local RF communicationcircuit 210. Indeed, even if the MEMS local RF communication circuit 250differs from the RF communication circuit 210, it nevertheless shouldemploy the same communication scheme.

[0057] The microcontroller 252 is configured to receive control datamessages via the RF communication circuit 250. In the embodimentdescribed herein, the control data messages are generated andtransmitted by the hub module 202. The control data messages typicallyinclude a control output value intended to control the operation of theactuator 262. Accordingly, the microcontroller 252 is operable to obtainthe control output value from a received message and provide the controloutput value to the signal processing circuit 256. The signal processingcircuit 256 is a circuit that is configured to generate an analogcontrol signal from the digital control output value. In other words,the signal processing circuit 256 operates as an analog driver circuit.The signal processing circuit 256 includes an output 258 for providingthe analog control signal to the actuator 262.

[0058] The non-volatile memory 254 is a memory that containsconfiguration and/or calibration information related to theimplementation of the actuator 262. The memory 254 may suitably containsufficient information to effect mapping between the control variablesused by the hub module 202 and the control signals expected by theactuator 262. For example, the control variables used by the hub module202 may be digital values representative of a desired damper positioncharge. The actuator 262, however, may expect an analog voltage thatrepresents an amount to rotate a stepper motor. The memory 254 includesinformation used to map the digital values to the expected analogvoltages.

[0059] The hub module 202 in the exemplary embodiment described hereinperforms the function of the loop controller (e.g. a PID controller) forthe space control subsystem 110. The hub module 202 obtains processvariable values (i.e. sensor information) from either or both of thesensor modules 204 and 206 and generates control output values. The hubmodule 202 provides the control output values to the actuator module208. The hub module 202 also communicates with external elements of thebuilding control system, for example, the supervisory computer, fan orchiller control subsystems, and other room controller subsystems.

[0060] In the exemplary embodiment described herein, the hub module 202further includes sensor functionality. In general, it is oftenadvantageous to combine the hub controller core functionality with asensor function to reduce the overall number of devices in the system.Thus, some room control subsystems could include hub module 202 with anintegrated temperature sensor and one or more actuator modules. Separatesensor modules such as the sensor module 204 would not be necessary.

[0061] To accomplish these and other functions, the hub module 202includes a network interface 270, a room control processor 272, anon-volatile memory 274, a signal processing circuit 276, a MEMS sensorsuite 278 and a MEMS local RF communication circuit 280.

[0062] The network interface 270 is a communication circuit thateffectuates communication to one or more components of the buildingcontrol system that are not a part of the space control subsystem 110.Referring to FIG. 1, the network interface 270 is the device that allowsthe space control subsystem 110 to communicate with the supervisorycomputer 102, the fan controller subsystem 106, the chiller controllersubsystem 108 and/or the other room controller subsystems.

[0063] Referring again to FIG. 2, to allow for wireless communicationbetween controller subsystems of the building control system 100, thenetwork interface 270 is preferably an RF modem configured tocommunicate using the wireless area network communication scheme.Preferably, the network interface 270 employs a packet-hopping protocolto reduce the overall transmission power required. In packet-hopping,each message may be transmitted through multiple intermediate networkinterfaces before it reaches its destination. Referring again to FIG. 1,if the space control subsystem 110 sends a message to the fan controlsubsystem 106, the network interface of the space control subsystem 110provides the message to the physically closest subsystem. Thus, in theembodiment shown in FIG. 1, the network interface of the space controlsubsystem 110 provides the message to the network interface of the spacecontrol subsystem 112. The network interface of the space controlsubsystem 112 reads the destination address of the message anddetermines that the message is not intended to be received at the spacecontrol subsystem 112. As a consequence, the network interface of thespace control subsystem 112 passes the message along to the networkinterface of the next closes subsystem, which is the space controlsubsystem 114. The network interface of the space control subsystem 114similarly passes the message onto the fan control subsystem 116. Thenetwork interface of the fan control subsystem 116, however, recognizesfrom the destination address in the message that it is the intendedrecipient. The network interface of the fan control subsystem 116 thusreceives the message and processes it.

[0064] Referring again to FIG. 2, in order to facilitate the wirelessarea network operation described above, the network interface 270 ispreferably operable to communicate using a short range wirelessprotocol. The network interface 270 is further operable to, either aloneor in conjunction with the control processor 272, interpret messages inwireless communications received from external devices and determinewhether the messages should be retransmitted to another external device,or processed internally to the hub module 202. As discussed above, if apacket-hopping protocol is employed, the network interface 270 mayreceive a message intended for another subsystem. In such a case, thenetwork interface 270 retransmits the message to another device.However, if the network interface 270 includes a temperature set pointfor the space control subsystem 110 of FIG. 2, then the networkinterface 270 passes the information to the room control processor 272.

[0065] As discussed above, the hub module 202 may optionally includesensor capability. To this end, the MEMS sensor suite 278 may suitablyinclude a plurality of MEMS sensors, for example, a temperature sensor,flow sensor, pressure sensor, and/or gas-specific sensor. As with thesensor modules 204 and 206, the hub module 202 may be programmed toenable the particular desired sensing capability. In this manner, asingle hub module design may be manufactured to for use in a variety ofHVAC sensing applications, each hub module 202 thereafter beingconfigured to its particular use. (See e.g. FIGS. 3 and 4). However, itmay be sufficient to provide hub control modules having only temperaturesensing capability because rooms that employ an HVAC controller alsotypically require a temperature sensor. Thus, a temperature sensor onthe hub module will nearly always fill a sensing need when the hubmodule is employed.

[0066] The signal processing circuit 276 includes the circuitry thatinterfaces with the sensor suite 278, converts analog sensor signals todigital signals, and provides the digital signals to the room controlprocessor 272. As discussed above, examples of low power,micro-electronic A/D converters and sensor interface circuitry are shownin the WINS Presentation.

[0067] The programmable non-volatile memory 274, which may be embodiedas a flash programmable EEPROM, stores configuration information for thehub module 274. By way of example, programmable non-volatile memory 274preferably includes system identification information, which is used toassociate the information generated by the sensor module 274 with itsphysical and/or logical location in the building control system. Thememory 274 further includes set-up configuration information related tothe type of sensor being used. The memory 274 may further includecalibration information regarding the sensor, and system RFcommunication parameters employed by the control processor 272, thenetwork interface 270 and/or the local RF communication circuit 280.

[0068] The MEMS local RF communication circuit 280 may suitably includea Bluetooth RF modem, or some other type of short range (about 30-100feet) RF communication modem. The MEMS local RF communication circuit280 is operable to communicate using the same RF communication scheme asthe MEMS local RF communication circuits 210, 230 and 250. As with thesensor module 204, the use of a MEMS-based RF communication circuitallows for reduced power consumption, thereby enabling the potential useof a true wireless, battery operated hub module 202. Moreover, it may bepossible and preferable to employ many of the same RF elements in boththe local RF communication circuit 280 and the network interface 270.Indeed in some cases, the local RF communication circuit 280 and thenetwork interface 270 are substantially the same circuit. In any event,a suitable MEMS-based RF communication circuit is discussed in the WINSPresentation.

[0069] The control processor 272 is a processing circuit operable tocontrol the general operation of the hub module 274. In addition, thecontrol processor 272 implements a control transfer function to generatecontrol output values that are provided to the actuator module 208 inthe space control subsystem 110. To this end, the control processor 272obtains sensor information from its own sensor suite 278 and/or fromsensor modules 204 and 206. The control processor 272 also receives aset point value, for example, from the supervisory computer 102 via thenetwork interface 270. The control processor 272 then generates thecontrol output value based on the set point value and one or more sensorvalues. The control processor 272 may suitably implement aproportional-integral-differential (PID) control algorithm to generatethe control output values. Suitable control algorithms that generatecontrol output values based on sensor or process values and set pointvalues are known.

[0070] Exemplary sets of operations of the room control system 110 isshown in FIGS. 3, 4 and 5. In general, FIGS. 3, 4 and 5 illustrate howthe hub module 202, the sensor module 204 and actuator 208 operate toattempt to control aspects of the environment of the room. Morespecifically, FIG. 3 shows an exemplary set of operations of the hubmodule 202, FIG. 4 shows an exemplary set of operations of the sensormodule 204, and FIG. 5 shows an exemplary set of operations of theactuator module 208.

[0071] Referring particularly to FIG. 3, the operations shown thereinwill be described with contemporaneous reference to FIG. 2. Theoperations of FIG. 3 are performed by the room control processor 272,which generally controls the operation of the hub module 202.

[0072] Steps 302, 304 and 306 all represent operations in which the roomcontrol processor 272 receives input values from various sources. Theorder in which those steps are performed is not of critical importance.

[0073] In step 302, the processor 272 receives a flow value from thesensor module 206, which in the exemplary embodiment described hereinhas been configured as a flow sensor module. To receive a flow valuefrom the sensor module 206, the processor 272 causes the local RFcommunication circuit 280 to be configured to receive a transmittedmessage from the local RF communication circuit 230 of the sensor module206. When a message is received, the local RF communication circuit 280and/or the processor 278 verify the source and intended destination ofthe message. If the message is legitimately intended for the hub module202, then the processor 278 parses the sensor value from the message forsubsequent use.

[0074] In step 304, the processor 272 receives temperature measurementvalues from the sensor module 204 as well as its internal temperaturesensor device 278. In many cases, only a single temperature sensor valueis necessary, in which case the hub module 202 need not include thetemperature sensor 278, or, alternatively, the sensor module 204 wouldnot be necessary. In the exemplary embodiment described herein, however,it will be assumed that the processor 272 receives temperature valuesfrom both the temperature sensor device 278 and the sensor module 204.To receive a temperature value from the sensor module 204, the processor272 and local RF communication circuit 280 operate in the same manner asthat described above in connection with receiving flow sensor valuesfrom the sensor module 206. To receive a temperature value from thesensor 278, the processor 272 receives digital sensor information fromthe signal processing circuit 276.

[0075] In step 306, the processor 272 obtains a set point value throughthe network interface 270. In particular, in the embodiment describedherein, the set point temperature for the room in which the controlsubsystem 110 is disposed is provided from a device external to thecontrol subsystem 110. For example, the supervisory computer 102 of FIG.1 may provide the temperature set points for all of the space controlsubsystems 110, 112 and 114 in the building control system 100. It willbe noted, however, that in alternative embodiments, the set point may bederived from a manually-adjustable mechanism directly connected to thehub module 202.

[0076] To receive the set point value from the external device, thenetwork interface 270 monitors transmissions in the WAN on which thevarious subsystems communicate. If a message including a set pointintended for the space control subsystem 110 is received by the networkinterface 270, then that message will be provided to the processor 272.In such a case, the processor 272 parses out the set point informationfor subsequent use, such as use in the execution of step 308, discussedbelow.

[0077] In step 308, the processor 272 generates a control output valuebased on the most recently received set point value and temperaturesensor values. To this end, the processor 272 may suitably employ a PIDcontroller algorithm to generate the control output value. In theembodiment described herein, the control output value is representativeof a desired change in a vent damper position. For example, if chilledair is provided through the vent, and the sensor temperature valueexceeds the set point temperature value, then the control output valueidentifies that the vent damper must be opened further. Further openingthe vent damper allows more chilled air to enter the room, therebyreducing the temperature.

[0078] A PID control algorithm that is capable of generating a ventdamper position based on a difference between temperature sensor valuesand a set point temperature value would be known to one of ordinaryskill in the art. In general, it will be noted that the use ofparticular control system elements such as temperature sensors, setpoint temperatures, and vent dampers are given by way of illustrativeexample. The use of control systems and subsystems with reduced wiringas generally described herein may be implemented in control systemsimplementing a variety of sensor devices and actuators or othercontrolled devices.

[0079] Referring again to the specific embodiment described herein, itwill be appreciated that during ongoing operation, the processor 272does not require an update in each of steps 302, 304 and 306 prior toperforming step 308. Any update received in any of those steps canjustify a recalculation of the control output value. Moreover, theprocessor 272 may recalculate the control output value on a scheduledbasis, without regard as to which input values have changed.

[0080] In step 310, the processor 272 causes the generated controloutput value to be communicated to the actuator module 208. To this end,the processor 272 and the local RF communication circuit 280 cooperateto generate a local RF signal that contains information representativeof the control output value. The processor 272 may suitably add adestination address representative of the actuator module 208 to enablethe actuator module 208 to identify the message.

[0081] It is noted that in the exemplary embodiment described herein,the flow sensor value received from the flow sensor module 206 is notused in the. PID control calculation performed by the processor 272.That value is obtained so that it may be used by other subsystems or bythe supervisory computer 102. Indeed, multiple sensor values aretypically communicated to external subsystems.

[0082] To this end, in step 312, the processor 272 causes the networkinterface 270 to transmit received sensor values to devices external tothe room control subsystem 110. For example, the processor 272 may causetemperature and flow sensor values to be transmitted to the supervisorycomputer 102. The supervisory computer 102 may then use the informationto monitor the operation of the building control system. Moreover,temperature and/or flow sensor values from various space controlsubsystems may be employed by the fan control subsystem 108 to adjustoperation of one or more ventilation fans, or by the chiller controlsubsystem 106 to adjust operation of the chiller plant. Accordingly, theprocessor 272 must from time to time cause sensor values generatedwithin the space control subsystem 110 to be communicated to externaldevices through the network interface 270.

[0083] The room control processor 272 repeats steps 302-312 on acontinuous basis. As discussed above, the steps 302-312 need not beperformed in any particular order. New sensor and/or set point valuesmay be received periodically either on a schedule, or in response torequests generated by the processor 272.

[0084] With regard to the sensor values, FIG. 4 shows an exemplary setof operations performed by the sensor module 204 in generating andtransmitting temperature sensor values to the hub module 202 inaccordance with step 302 of FIG. 3. The sensor module 206 may suitablyperform a similar set of operations to generate and transmit flow sensorvalues to the hub module 202 in accordance with step 304 of FIG. 3.

[0085] Referring now to FIG. 4, the operations shown therein areperformed by the microcontroller 212 of the sensor module 204. In step402, the microcontroller 212 determines whether it is time to transmitan updated temperature value to the hub module 202. The determination ofwhen to transmit temperature values may be driven by a clock internal tothe sensor module 204, or in response to a request or query receivedfrom the hub module 202, or both. In either event, if it is not time totransmit an update, the microcontroller 212 repeats step 402.

[0086] If, however, it is determined that an update should betransmitted, then the microcontroller 212 proceeds to step 404. In step404, the microcontroller 212 obtains a digital value representative of ameasured temperature from the signal processing circuit 216. To thisend, the microcontroller 212 preferably “wakes up” from a power savingmode. The microcontroller 212 preferably also causes bias power to beconnected to power consuming circuits in the signal processing circuit216, such as the A/D converter. In this manner, power may be conservedby only activating power consuming circuits when a temperature sensorvalue is specifically required. Otherwise, the power consuming devicesremain deactivated. Thus, for example, if a temperature value need onlybe updated every fifteen seconds, many of the power consuming circuitswould only be energized once every fifteen seconds. However, it is notedthat if the power source 220 is derived from AC building power, the needto reduce power consumption is reduced, and the microcontroller 212 andthe signal processing circuit 216 may receive and process digitaltemperature sensing values on an ongoing basis.

[0087] In any event, after step 404, the microcontroller 212 proceeds tostep 406. In step 406, the microcontroller 212 converts the senseddigital temperature value into the format expected by the room controlprocessor 272 of the hub module 202. The microcontroller 212 furtherprepares the message for transmission by the local RF communicationcircuit 210. Once the message including the sensor temperature value isprepared, the microcontroller 212 in step 408 causes the local RFcommunication circuit 210 to transmit the message. The message isthereafter received by the hub module 202 (see step 304 of FIG. 3).Thereafter, the microcontroller 212 may return to step 402 to determinethe next time an update is required.

[0088]FIG. 5 shows an exemplary set of operations that may be performedby the microcontroller 252 of the actuator module 208. As discussedabove, one purpose of the space control subsystem 110 is to control thephysical operation of a device to help regulate a process variable, inthis case, the room temperature. The actuator module 208 thus operatesto carry out the actions determined to be necessary in accordance withthe control algorithm implemented by the room process controller 272.

[0089] First, in step 502, a message which may include the controloutput value is received from the hub module 202. To this end, the RFcommunication circuit 250 receives the message and provides the messageto the microcontroller 252. Thereafter, in step 504, the microcontroller252 determines whether the received message is intended for receipt bythe actuator module 208. If not, then the microcontroller 252 returns tostep 502 to await another incoming message.

[0090] If, however, the microcontroller 252 determines in step 504 thatthe received message is intended for the actuator module 208, then themicrocontroller 252 proceeds to step 506. In step 506, themicrocontroller 252 parses the message to obtain the actuator controloutput value, and converts that value into a value that will cause theactuator to perform the requested adjustment. For example, if thereceived control output value identifies that the ventilator dampershould be opened another 10%, then the microcontroller 252 wouldgenerate a digital output value that, after being converted to analog inthe signal processing circuit 256, will cause the actuator 258 to openthe ventilator damper another 10%.

[0091] In step 508, the microcontroller 252 actually provides thedigital output value to the signal processing circuit 256. The signalprocessing circuit 256 then converts the value to the correspondinganalog voltage expected by the actuator device 258. Thereafter, themicrocontroller 252 returns to step 502 to await the next messagereceived from the hub module 202.

[0092] The above described space control subsystem 110 is merely anexemplary illustration of the principles of the invention. Theprinciples of the invention may readily be applied to control subsystemshaving more or less sensors or actuators, as well as other elements.

[0093] The relatively low power requirements enabled by the use of MEMSdevices and local RF communications in the sensor modules and even thehub module allow for implementation of the modules in battery operatedformat. Thus, a mostly wireless building control system may bedeveloped. However, as discussed above, many advantages of the presentinvention may be obtained in systems that use other forms of power.

[0094]FIG. 6 shows an exemplary embodiment of the space controlsubsystem 114 of the building control system 100 of FIG. 1. The spacecontrol subsystem 114 of FIG. 6 is used in a space or room 610 thatincludes two fume hoods 612 and 614. A fume hood, as is known in theart, is a fume collection device disposed over an enclosed surface. Thefume hoods 612 and 614 allow for experiments or processes that involvenoxious gasses fumes by conducting those gasses away from theexperimental area.

[0095] The room 610 is coupled in an air communication relationship withan air flow supply duct 618 in which are disposed a supply damper 620and a radiator or heating coil device 616. The room 610 is also coupledto communicate air to an exhaust duct 622 through a main exhaust damper624. Fume hood dampers 626 and 628 communicate air/gas within the fumehoods 612 and 614, respectively, to the exhaust duct 622.

[0096] The space control subsystem 114 is designed to both regulate thetemperature within the room 610 as well as ensure that the fume hoods612 and 614 achieve their purpose in conducting away gasses. Forordinary temperature regulation, the space control subsystem 114controls the operation of the supply damper 620 and the heating coil 616to control the supply of heated or cooled air into the room 610. Thespace control subsystem 114 control the main exhaust damper 624 in acoordinated fashion with the supply damper 620 to ensure sufficientfresh air and proper atmospheric pressure is maintained within the room610. For conducting away noxious gasses, the space control subsystem 114controls the operation of the fume hood dampers 626 and 628 to conductgasses away when their presence is detected. The supply damper 620and/or the main exhaust damper 624 is also controlled in a coordinatedmanner to ensure that the required air flow to conduct gasses away isavailable through the appropriate fume hood damper 626 or 628.

[0097] To this end, the space control subsystem 114 includes a controlmodule 630, a supply flow module 632, a main exhaust module 634, a firstfume hood exhaust module 636, a second fume hood exhaust module 638, afirst fume hood sensor module 640, and a second fume hood sensor module642.

[0098] The control module 620 generally operates to effectuatecommunication between the space control subsystem 114 and the othersubsystems of the building control system 100 (see FIG. 1). In theembodiment described herein, the control module 620 further includes atemperature sensor. The supply flow module 632 controls the supplydamper 620 to regulate the supply of air flow into the space 610, andfurther controls the supply of heat (or cool) water to the heating coilelement 616 disposed in the path of the air flow supply. The mainexhaust module 634 controls the main exhaust damper 624 to regulate theflow of air out of the space 610, such that in general the atmosphericpressure within the room is controlled by the cooperative efforts of thesupply flow module 622 and the main exhaust module 624.

[0099] The first fume hood exhaust module 636 controls the damper 626 tocontrol the exhaust or venting of fumes or gas from within or in thevicinity of the fume hood 612. The second fume hood exhaust module 638controls the damper 628 to control the exhaust or venting of fumes orgas from within or in the vicinity of the fume hood 614. The first fumehood sensor module 640 is operable to obtain measurements indicative ofthe concentration of a gas within the fume hood 612, while the secondfume hood sensor module 642 is operable to obtain measurementsindicative of the concentration of a gas with the fume hood 614.

[0100]FIGS. 7a-b, 8 a-c, 9 a-b, 10 a-b and 11 a-b describe the structureand operation of the various modules 630 through 642 of the spacecontrol subsystem 114 in order to carry out the above described controloperations. In particular, FIGS. 7a and 7 b describe the structure andoperation of the control module 630, FIGS. 8a, 8 b and 8 c describe thestructure and operation of the supply module 632, FIGS. 9a and 9 bdescribe the structure and operation of the main exhaust module 634,FIGS. 10a and 10 b describe the structure and operation of the firstfume hood sensor module 640 (which is also applicable to the second fumehood sensor module 642), and FIGS. 11a and 11 b describe the structureand operation of the first fume hood exhaust module 636 (which is alsoapplicable to the second fume hood exhaust module 638).

[0101] Preferably, all of the modules 630, 632, 634, 636, 638, 640 and642 are constructed of a uniform basic module design, and thenindividually configured to carry out the particular operations describedbelow. To this end, FIGS. 12a and 12 b show an exemplary embodiment of aflexible, MEMS-based module design that is particularly useful inbuilding control, automation, comfort, security and/or safety systems.

[0102] Referring to FIGS. 12a and 12 b, the module 1200 is implementedas a single, self-powered, standalone device in which most of the activecomponents are integrated onto one or two semiconductor substrates.

[0103] As shown in FIG. 12a, the module 1200 in the embodiment describedherein includes a top semiconductor layer 1202, a lithium ion batterylayer 1204 and a bottom semiconductor layer 1206. The various functionsof the module 1200, discussed below in connection with FIG. 12b, areincorporated into the top and bottom semiconductor layers 1202 and 1206.The lithium ion battery layer 1204 provides a source of electrical powerto the top and bottom semiconductor layers 1202 and 1206. The lithiumion battery layer 1204 is preferably disposed between the top and bottomsemiconductor layers 1202 and 1206 to provide an advantageous,space-efficient layout. Various interconnects may be provided betweenthe two semiconductor layers 1202 and 1206 around the lithium ionbattery layer 1204 as need. In the alternative, one of the two layersmay be dedicated completely to a light-powered recharging circuit forthe lithium ion battery layer 1204. In another alternative, all of theelements of the module 1200 may be implemented onto a singlesemiconductor substrate such as the layer 1202.

[0104]FIG. 12b shows a block diagram representation of the modulecircuits 1250 that are implemented into the semiconductor layers 1202and 1206 of the module 1200. The module circuit 1250 include a sensorsuite 1252, an EEPROM 1254, a processing circuit 1256, a powermanagement circuit 1258 and an RF communication circuit 1260.

[0105] The RF communication circuit 1260 is a MEMS based communicationcircuit such as that described above in connection with FIG. 2. The RFcommunication circuit 1260 is preferably configured to communicate usingat least one local RF communication format, such as Bluetooth.

[0106] The power management circuit 1258 that preferably operates torecharge the lithium ion battery layer 1204 of FIG. 6, and may includesemiconductor devices that convert light or RF energy into electricalenergy that may be used to trickle charge the lithium ion battery.

[0107] The sensor suite 1252 is collection of MEMS sensors incorporatedinto a single substrate. The incorporation of multiple MEMS sensortechnologies is known. For example, Hydrometrics offers for sale a MEMSsensor device that includes both temperature and humidity sensingfunctions. MEMS based light, gas content, temperature, flow, smoke andother sensing devices are known. Such devices are in the embodimentdescribed herein implemented onto a single substrate 1202 or 1206, orpair of substrates 1202 and 1206.

[0108] The processing circuit 1256 incorporates a microprocessor ormicrocontroller, as well as microelectronics A/D circuits for connectingto the MEMS sensor devices of the sensor suite 1252. As such, theprocessing circuit 1256 performs the operations described above inconnection with the signal processing circuit 216 and controller 212 ofthe sensor module 204 of FIG. 2.

[0109] The EEPROM 1254 (which may be another type of non-volatile,chip-based memory such as ferro-electric or ferro-magnetic RAM) is anon-volatile memory that stores the configuration information for themodule 1200. For example, the EEPROM 1254 may store ID information usedto identify the module 1200 to the system in which it is connected. TheEEPROM 1254 also stores information related to the function in which themodule 1200 will be used. For example, the EEPROM 1254 may storeinformation identifying that the module 1200 should enable itstemperature sensing function as opposed to any of its other possiblesensing functions.

[0110] As discussed above in connection with FIG. 2, the configurationinformation in the EEPROM 1254 may simply identify the intendedfunctionality of the module 1200, which would then cause the processingcircuit 1256 to execute portions of program code stored in ROM (notshown) to carry out that identified functionality. To this end, theEEPROM 1254 may be replaced by a set of DIP switches that may bemanually manipulated to set the configuration of the module 1200. Ineither case, such embodiments would require that most of the programcode for a variety of different sensor functions be stored in ROM, onlya portion of which would be used once the configuration information isreceived.

[0111] However, in one embodiment of the invention, most or all of thecode unique to the selected function of the module is downloaded intothe EEPROM 1254 during configuration of the device. Thus, if the module1200 is to operate as a temperature sensor module, then all appropriatecode for a temperature sensor module is downloaded to the EEPROM 1254,as is identification information and calibration information. Thismethod provide maximum flexibility because a single module 1200 may beprogrammed to do many custom tailored tasks, in addition to performingsensor functions.

[0112] Regardless of whether the EEPROM 1254 is configured via largeamounts of programming code, or through flags and parameters that areused to select pre-existing code within the module 1200, theconfiguration information is downloaded to the EEPROM 1254 from anexternal device, for example, a portable programming device. Inparticular, a portable programming device provides programminginstructions via RF signals to the RF communication circuit 1260. Theprocessing circuit 1256 obtains the programming instructions from the RFcommunication circuit 1260 and stores the instructions into the EEPROM1254. It will be appreciated that other techniques for providingconfiguration information to the EEPROM 1254 may be used.

[0113] Thus, the above described module 1200 may readily be configuredas any one of a large plurality of sensor types or even other types ofbuilding automation system components. As a consequence, large amountsof the devices may be fabricated, thereby reducing the per-unit toolingand design costs associated with ordinary building automation sensors.In addition, the highly integrated nature of the devices reducesshipping and storage costs, as well as reduces power consumption. Itwill be noted that the design of the module 1200 may be used as thesensor modules 204, 206 in the exemplary space control subsystem 200 ofFIG. 2, and may also be used as the hub module 202. In such a case, thenetwork interface 270 of the hub module 202 may be configured to operatevia the RF communication circuit 1260 of the module 1200 of FIGS. 12aand 12 b.

[0114] Returning now to the discussion of the subsystem 114 of FIG. 6,it will be assumed that in the embodiment described herein that themodules 630, 632, 634, 636, 638, 640 and 642 all employ the design andconstruction of the module 1200 of FIGS. 12a and 12 b. However, it willbe appreciated that other assemblies of those circuits may be employedand achieve at least some of the benefits of the invention.

[0115] The individual modules 630, 632, 634, 636, 638, 640 and 642 ofFIG. 6 are now described in further detail.

[0116] Referring to the control module 630, FIG. 7a shows an exemplaryblock diagram of the control module 630, while FIG. 7b shows anexemplary flow diagram of the operations performed by the controlprocessor of the control module 630. In the exemplary embodimentdescribe herein, the control module 630 cooperates with the supplymodule 632 and main exhaust module 634 to control the temperature in theroom 610. As discussed above, the control module 630 also facilitatescommunication of information, if necessary, between any of the modules630-642 and elements of other subsystems of the building control system100 (see FIG. 1).

[0117] As discussed above, the control module 630 has a generalconstruction substantially similar to the module 1200 of FIGS. 12a and12 b. To this end, the control module 630 includes an RF communicationcircuit 705, a power management circuit 710, a processing circuit 715,an EEPROM 720, and a sensor suite 725. Each of the elements of thecontrol module operates generally as described above in connection withFIGS. 12a and 12 b.

[0118] The control module 630 includes a temperature sensingfunctionality. As a consequence, the EEPROM 720 includes configurationinformation identifying that processing circuit 715 should obtain andprocess temperature measurement information from the MEMS sensor suit725. In the exemplary embodiment described herein, the EEPROM 720further includes sufficient program instructions or code to carry outthe operations illustrated in FIG. 7b and described below.

[0119] The RF communication circuit 705 is preferably configured tocommunicate with the other elements of the subsystem 114 as well as inthe local area network between subsystems. To this end, the RFcommunication circuit 705 may be able to communicate using the twodifferent communication schemes described above in connection with FIGS.1 and 2. In particular, one scheme would be used for communicationswithin the subsystem 114 and the other scheme would be used tocommunicate to other subsystems and devices external to the subsystem114. Alternatively, the RF communication circuit 705 may insteadcommunicate using only a single RF communication scheme. Externalcommunications would be carried out through a separate network interfacedevice, not shown, that is itself capable of communicating using the twodifferent communication schemes.

[0120] The operation of the control module 630 is described withreference to FIG. 7b, which shows an overview of the functions of theprocessing circuit 715. With reference to FIG. 7b, in step 750, theprocessing circuit 715 receives from time to time a room temperature setpoint value W_(T). To this end, the RF communication circuit 705receives the information within communication signals from one or moredevices external to the subsystem 114 such as, for example, thesupervisory computer 102 of FIG. 1. The RF communication circuit 705then provides the information to the processing circuit 715.Alternatively, all or part of the temperature set point may be providedvia a manual control device disposed within the room 610.

[0121] Also in step 750 the processing circuit 715 receives the setpoints W_(G1FL) and W_(G2FL) from, respectively the fume hood exhaustmodules 636 and 638. The processing circuit 715 also receives themeasured exhaust flow X_(FLO) from the main exhaust module 634. Theprocessing circuit 715 receives such information from transmitted RFsignals from the modules 634, 636 and 638 via the RF communicationcircuit 705.

[0122] Referring to FIG. 6, the set points W_(G1FL) and W_(G2FL)represent the exhaust air flow through the exhaust dampers 626 and 628from the fume hoods 612 and 614, respectively. As discussed below inconnection with step 770, the control module 630 uses the valuesW_(G1FL) and W_(G2FL) to adjust the supply flow to accommodate anyadditional outflow through the dampers 626 and 628. In particular,whenever it becomes necessary to vent fumes through the fume hood viaeither of the dampers 626 or 628, the supply flow at the supply damper620 is increased to provide additional air pressure to force air flowthrough the dampers 626 and/or 628. However, it will be appreciated thatinstead of increasing the supply flow when it becomes necessary to ventfumes through the fume hood(s), the supply flow may remain constant andthe main exhaust damper 624 may be further closed or restricted to forceexhaust air flow through the fume hood exhaust dampers 626 and/or 628.Alternatively, a combination of partially closing off the main exhaustdamper 624 and further opening the supply damper 620 may be used.However, in the exemplary embodiment described herein, the supply damper620 is adjusted to compensate for additional (or decreased) flow causeby opening (or closing) the fume hood exhaust dampers 626 and/or 628.For this reason, the processing circuit 715 receives W_(G1FL) andW_(G2FL) in step 750, as well as W_(T).

[0123] In step 755, the processing circuit 715 also receives from timeto time a room temperature measurement value X_(T). To this end, theprocessing circuit 715 obtains an analog temperature measurement valuefrom the temperature sensor element within the MEMS sensor suite 725 andconverts the analog temperature measurement value to a representativedigital value thereof X_(T).

[0124] In step 760, the processing circuit 715 generates a temperaturecontrol output value Y_(T). The value Y_(T) actually represents aninterim value in the system indicative of how the system must change toachieve the temperature set point W_(T). Thus, Y_(T) is a function ofW_(T) and X_(T). By way of a simple example, Y_(T) may suitably be setto the error signal W_(T)-X_(T).

[0125] Thereafter in step 765, the processing circuit 715 calculates themain exhaust set point W_(FLO) based on the current exhaust X_(FLO) andthe temperature control output Y_(T). The function that determinesW_(FLO) carries out the operations set forth below.

[0126] In general, if the temperature is too high within the room 610(i.e. Y_(T) is a negative number), then additional cool air should besupplied to the room 610. It is assumed that the supply duct 618 movescooling air into the room 610 when the heating coil 616 is not actuated.Thus, if Y_(T) is a negative number, then the additional flow from thesupply duct 618 is required. Instead of directly increasing the supplyflow, however, the main exhaust flow set point W_(FLO) is increased instep 765. As will be discussed below in connection with step 770, thesupply flow set point, W_(FL), will also be adjusted accordingly. Theresulting increase in the supply flow and exhaust flow moves more coolair into the room, thereby reducing the temperature within the room.

[0127] If, instead, the temperature is too low within the room 610,(i.e. Y_(T) is a positive number), then the flow of cool air from thesupply duct 618 should be decreased. To this end, the main exhaust flowset point W_(FLO) is adjusted downward, if possible. The reduction inthe exhaust flow and corresponding reduction in supply flow (see step770) reduces the flow of cool air into the room 610 and should result inan increase in the temperature. If, the main exhaust flow is alreadyminimized, in other words, the main exhaust damper 624 is substantiallyclosed, then the main exhaust flow set point W_(FLO) cannot be adjustedfurther downward. The determination as to whether the main exhaustdamper 624 is substantially closed is based on the exhaust flow X_(FLO)value.

[0128] The above described functionality of step 765 may readily becarried out by any number of suitable function definitions thatdetermine W_(FLO) based on Y_(T) and X_(FLO).

[0129] In step 770, the processing circuit 715 calculates the supplyflow set point W_(FL) based on the exhaust flow set point W_(FLO) andthe two fume hood exhaust flow set points, W_(G1FL) and W_(G2FL). Tothis end, it will be appreciated that in the exemplary embodiment shownin FIG. 6, the total air flowing out of the room 610 flows through themain exhaust damper 624, the first fume hood exhaust damper 626 and thesecond fume hood exhaust damper 628. Accordingly, to avoid undulypressurizing and/or depressurizing the room, the supply flow set pointW_(FL) is set to accommodate to the three exhaust flow set points. In asimple example, W_(FL)=W_(FLO)+W_(G1FL)+W_(G2FL).

[0130] It will be appreciated that as the exhaust flow W_(FLO) isincreased or decreased in step 765, the supply flow exhaust point W_(FL)should increase or decrease accordingly.

[0131] Likewise, the supply flow increases or decreases responsive tothe change of either of the fume hood exhausts. For example, if the fumehood 612 must be vented, then the first fume hood exhaust flow set pointW_(G1FL) is increased (see FIGS. 10 and 11) and the supply flow setpoint W_(FL) is increased accordingly. As a consequence, the subsystem114 automatically increases air flow into the room 610 to supply theneeded additional pressure to vent fumes through the fume hood exhaustdampers 626 and/or 628.

[0132] Thus, in step 770, the supply flow set point W_(FL) is setresponsive to based on the exhaust flow set points W_(FLO), W_(G1FL),and W_(G2FL).

[0133] In step 775, the processing circuit 715 determines the heatingcoil set point W_(HC) based on the temperature control value Y_(T) andthe supply flow set point W_(FL). In general, if the temperature in theroom remains low (i.e. Y_(T) is positive) for a long time, it isindicative that the attempts to raise the temperature through control ofthe air flow (in steps 765 and 770) were not successful. In such a case,the heating coil 616 should be turned on. To this end, the heating coilset point W_(HC) is determined based on the value of Y_(T) over time. Inaddition, the amount of heating provided by the convection air flow overthe heating coil 616 depends in part on the air flow rate past theheating coil 616. Accordingly, the heating coil set point W_(HC) is alsopreferably determined as a function of the supply flow set point W_(FL).

[0134] Thus, the above steps 765 and 770 regulate the supply flow ofcooler air into the room 610 to control the temperature. However, ifsuch regulation cannot adequately raise the temperature of the room 610,then the heating coil 616 is used to help regulate temperature in step775. For example, the supply flow of cooler air in some cases cannot bereduced (to raise room temperature) because of the need for air flow tovent gasses out of the fume hoods 612 and/or 614. Thus, even though alow temperature may indicate that the supply flow should be reduced, thesupply flow cannot be reduced without jeopardizing fume hood operation.In such cases, the heating coil 616 is actuated and the supply flowactually provides warm air that raises the room temperature.

[0135] It will be appreciated that other methods may be used to regulatetemperature within a space or room while adjusting the supply flowand/or exhaust flow to compensate for the need to vent air through thefume hoods 612 and/or 614.

[0136] In any event, in step 780, the processing circuit 715 causes theRF communication circuit 705 to communicate the room flow set pointW_(FL) and the heating coil set point W_(HC) to the supply flow module632, and to communicate the exhaust flow set point W_(FLO) to the mainexhaust module 634. Operation of the supply flow module 632 is discussedbelow in connection with FIGS. 8a, 8 b and 8 c. Operation of the mainexhaust module 634 is discussed below in connection with FIGS. 9a and 9b.

[0137] The processing circuit 715 thereafter periodically receivesupdates of X_(FLO), W_(G1FL), W_(G2FL), and/or W_(T) via the RFcommunication circuit 705, and updates of the measured temperature X_(T)from the sensor suite 725. While these updates are typicallyinterrupt-based, such that reception of one of the values causesrecalculation of one or more of the values W_(FLO), W_(FL) or W_(HC),another suitable update and recalculation scheme would involveperiodically requesting updates to any or all of W_(G1FL), W_(G2FL),W_(T) and/or X_(T). In either event, upon receiving one or more updates,the processing circuit 715 preferably repeats of steps 760, 765, 770,775 and 780.

[0138] It will thus be noted that the steps 750 through 780 need not beexecuted in the order illustrated in FIG. 7b, nor must both steps 750and 755 be executed prior to each subsequent execution of steps 760through 780. However, over the course of operation, steps 750 through780 will be executed repeatedly.

[0139] The above steps illustrate how the control module 630 maydetermine the set point for the supply flow damper 620, the exhaust flowdamper 624 and the heater coil 616 in order to control the roomtemperature. It will be appreciated that the control module 730 mayreadily be adapted to other methods to control the temperature. Thecontrol module 630 further adjusts the supply flow as necessary tocompensate for the need for additional air flow to vent fumes out ofthis exhaust dampers 626 and/or 628.

[0140] It is noted, however, that the control module 730 does notdirectly cause actuators of the heating coil or air flow equipment toact. Instead, the control module 730 merely obtains the set points,W_(FLO), W_(FL) and W_(HC), for such equipment. The actuators for thesupply damper 620 and heater coil 616 are controlled by the supply flowmodule 632. The actuator for the main exhaust damper 624 is controlledby the main exhaust module 634.

[0141] Referring now specifically to FIG. 8a, the supply flow module 632has a general construction substantially similar to the module 550 ofFIGS. 12a and 12 b. To this end, the supply flow module 632 includes anRF communication circuit 805, a power management circuit 810, anprocessing circuit 815, an EEPROM 820, and a sensor suite 825. Each ofthe elements of the control module operates generally as described abovein connection with FIGS. 12a and 12 b.

[0142] The control module 830 includes a flow sensing functionality, andis further configured to generate actuator output signals. The actuatoroutput signals may suitably be provided as analog output pins 815 a, 815b on the processing circuit 815. The actuator output signals are analogoutputs that control the operation of actuators for the heating coil 616and the damper 620. To this end, the analog output pins 815 a and 815 bare connected to external actuators 817 and 818.

[0143] To enable the flow sensing functionality, the EEPROM 820 includesconfiguration information identifying that the processing circuit 815should obtain an air flow measurement information from the MEMS sensorsuit 825. In the exemplary embodiment described herein, the EEPROM 820further includes sufficient program instructions or code to carry outthe operations illustrated in FIGS. 8b and 8 c and described below.

[0144] The RF communication circuit 805 is preferably configured tocommunicate with the other elements of the subsystem 114. As discussedabove, the RF communication circuit 805 may suitably be configured touse Bluetooth or another local RF communication protocol.

[0145] The operation of the supply flow module 632 is described withreference to FIGS. 8b and 8 c, which show an overview of two separatefunctions of the processing circuit 815. FIG. 8b shows the functionrelated to regulation of the supply air flow in the room 610 while FIG.8c shows the function related to control of the heater coil 616.

[0146] With reference to FIG. 8b, in step 850, the processing circuit815 receives from time to time (via the RF communication circuit 805)the set points W_(FL) and W_(HC) from the control module 630. The use ofthe heating coil set point W_(HC) is discussed further below inconnection with step 880 of FIG. 8c.

[0147] In step 855, the processing circuit 815 also receives a supplyair flow measurement value X_(FL). To this end, the processing circuit815 obtains an analog flow measurement value from the flow sensorelement within the MEMS sensor suite 825 and converts the analog flowmeasurement value to a digital value representative thereof, X_(FL).

[0148] In step 860, the processing circuit 815 calculates a supply flowdamper control output Y_(FL) based on the measured flow X_(FL) and theset point value W_(FL). To this end, the processing circuit 815 may usean ordinary PID algorithm.

[0149] In step 865, the processing circuit 815 provides an actuatoroutput signal corresponding to Y_(FL) to its output 815 a, which in turnprovides to the actuator 817 that causes mechanical adjustment of thesupply flow damper 620.

[0150] As with the processing circuit 715 of FIG. 7a, the processingcircuit 815 thereafter periodically receives updates of its inputs andrecalculates the output value of step 860. Steps 850, 855, 860 and 865need not be executed in the order illustrated in FIG. 8b.

[0151]FIG. 8c shows a flow diagram of the steps of the processingcircuit 815 in controlling the actuator 818 of the heater coil 616. Instep 880, the processing circuit 815 receives the heating coil set pointW_(HC) through the RF communication circuit 805. The processing circuit815 thereafter in step 885 sets the actuator control output Y_(HC) tovalue that is the functional equivalent of W_(HC) and provides Y_(HC) tothe output 815 b. The heating coil actuator control output Y_(HC) thenpropagates to the actuator 818. The actuator 818 thereafter affects theoperation of the heating coil 616 in a manner responsive to the controloutput Y_(HC) in a manner that would be known to those of ordinary skillin the art.

[0152] The processing circuit 815 may thereafter receive periodicupdates, via request or otherwise, and then repeat steps 880 and 885.Steps 880 and 885 may suitably executed independently of steps of thesteps of FIG. 8b.

[0153] The above operations of the processing circuit 815 cause thesupply flow module 632 to control both the heating coil 616 and thesupply flow damper 620 to regulate the temperature and fresh air supplyinto the room 610. As discussed above, the processing circuit 815 useslocal RF communications to obtain the necessary set points and otherdata to carry out the operations. In addition, the processing circuit815 communicates exhaust flow information to the main exhaust module624.

[0154] As referenced further above, FIGS. 9a and 9 b show the structureand operation of the main exhaust module 634. The main exhaust controlmodule 634 effectively controls the main exhaust damper 624 to helpregulate the removal of “spent” air that is being replace with “fresh”air through the supply conduit 618. As is known in the art, fresh air ispreferably supplied to the room 610 even in the absence of noxious fumesor gas, particularly to provide cooling air to maintain a steadytemperature into the room.

[0155] Referring now specifically to FIG. 9a, the main exhaust module634 has a general construction substantially similar to the module 120of FIGS. 12a and 12 b. To this end, the main exhaust module 634 includesan RF communication circuit 905, a power management circuit 910, anprocessing circuit 915, an EEPROM 920, and a sensor suite 925. Each ofthe elements of the main exhaust module 634 operates generally asdescribed above in connection with FIGS. 12a and 12 b.

[0156] The main exhaust module 634 includes a flow sensingfunctionality, and is further configured to generate an actuator outputsignal. The actuator output signal may suitably be provided as analogoutput pin 915 a on the processing circuit 915. The actuator outputsignal is an analog output that controls the operation of actuator forthe damper 624. To this end, the analog output pin 815 a is connected toan external actuator 917, which in turn controls the position of thedamper 624.

[0157] To enable the flow sensing functionality, the EEPROM 920 includesconfiguration information identifying that the processing circuit 915should obtain an air flow measurement information from the MEMS sensorsuite 925. In the exemplary embodiment described herein, the EEPROM 920further includes sufficient program instructions or code to carry outthe operations illustrated in FIG. 9b and described below.

[0158] The RF communication circuit 905 is preferably configured tocommunicate with the other elements of the subsystem 114. As discussedabove, the RF communication circuit 905 may suitably be configured touse Bluetooth or another local RF communication protocol.

[0159] The operation of the main exhaust control module 634 is describedwith reference to FIG. 9b, which shows an overview of the functions ofthe processing circuit 915. As shown in FIG. 9b, in step 950, theprocessing circuit 915 receives from time to time (via the RFcommunication circuit 905) the main exhaust set point W_(FLO), which isprovided by the control module 630, as discussed above.

[0160] In step 955, the processing circuit 915 receives a main exhaustflow measurement X_(FLO). To this end, the processing circuit 915obtains an analog flow measurement value from the flow sensor elementwithin the MEMS sensor suite 925 and converts the analog flowmeasurement value to a digital value representative thereof X_(FLO).

[0161] In step 960, the processing circuit 915 calculates a main exhaustdamper control output Y_(FLO) based on the measured flow X_(FLO) and theset point value W_(FLO). To this end, the processing circuit 915 may usean ordinary PID algorithm.

[0162] In step 965, the processing circuit 915 provides an actuatoroutput signal corresponding to Y_(FLO) to its output 915 a, which inturn provides the actuator output signal to the actuator 917. Theactuator 917 causes mechanical adjustment of the main exhaust damper 624responsive to the actuator output signal.

[0163] In step 970, the processing circuit 915 causes the RFcommunication circuit 970 to communicate the measured flow value X_(FLO)to the control module 630.

[0164] The processing circuit 915 thereafter periodically receivesupdates of its inputs and recalculates the actuator output signal. Inother words, steps 950-970 are periodically repeated.

[0165] The above operations of the processing circuit 915 operate tocontrol the main exhaust of “spent” air to the room based on the setpoint W_(FLO) generated by the control module 632. (See FIG. 8b).Alternative calculations of the exhaust flow set point W_(FLO) may bemade. As discussed further above, in alternative embodiments, the mainexhaust flow may be adjusted to redirect air flow through the fume hoodexhaust dampers 626 and/or 628. Regardless, one feature of thisembodiment of the invention is that balance between the supply flow andthe main exhaust flow is adjusted in response to a need to vent air orgas through the fume hood exhausts.

[0166]FIGS. 10a and 10 b show the structure and operation of the firstfume hood sensor module 640. The first fume hood sensor module 640effectively measures the concentration of one or more select noxiousgasses within the first fume hood 612. It will be appreciated that thesecond fume hood sensor module 642 has a substantially similarconstruction and operates in a substantially similar way.

[0167] Referring now specifically to FIG. 10a, the first fume hoodsensor module 640 has a general construction substantially similar tothe module 1200 of FIGS. 12a and 12 b. To this end, the first fume hoodsensor module 640 includes an RF communication circuit 1005, a powermanagement circuit 1010, an processing circuit 1015, an EEPROM 1020, anda sensor suite 1025. Each of the elements of the first fume hood sensormodule 640 operates generally as described above in connection withFIGS. 12a and 12 b.

[0168] The first fume hood sensor module 640 includes a gasconcentration sensing functionality. The gas may be any of a number ofnoxious gasses. As discussed further above, various MEMS sensors devicesare known that detect the concentration of various gasses. Thus, forexample, the sensor suite 1025 may suitable include a plurality ofgas-specific sensors. To enable the gas sensing functionality, theEEPROM 1020 includes configuration information identifying that theprocessing circuit 1015 should obtain gas concentration measurementinformation for one or more gasses from the MEMS sensor suite 1025. Itis noted that the gas sensing functionality should correspond to thetypes of noxious gas or gasses expected to be generated within the fumehood 612. With the configurable EEPROM 1020, the module 640 may bereconfigured if the type of noxious gas generated within the fume hood612 changes.

[0169] In the alternative, the first fume hood sensor module 640 mayinclude a MEMs-based gas chromatography element in the sensor suite1025. Such an element can provide gas chromatographic information to theprocessing circuit 1015. The processing circuit 1015 may then analyzethe information for specific gas content. The EEPROM 1020 would provideconfiguration information as to which gasses to monitor. A suitableMEMs-based gas chromatography device is the “Lab on a Chip” availablefrom Argon National Laboratories. Others are known in the art.

[0170] In yet another embodiment, using gas chromatography or similargas content analysis, the configuration information of the EEPROM 1020may identify a template defining breathable air, for example, havingspecific ranges of oxygen, nitrogen and carbon dioxide. The processingcircuit 1015 uses this template to determine whether the oxygen,nitrogen and/or other breathable air gasses are within predefinedlimits. If not, then X_(G1) would be given a value that indicates theneed for additional venting.

[0171] In any event, in the exemplary embodiment described herein, theEEPROM 1020 further includes sufficient program instructions or code tocarry out the operations illustrated in FIG. 10b and described below.

[0172] The RF communication circuit 1005 is preferably configured tocommunicate with the other elements of the subsystem 114. As discussedabove, the RF communication circuit 1005 may suitably be configured touse Bluetooth or another local RF communication protocol.

[0173] The operation of the first fume hood sensor module 640 isdescribed with reference to FIG. 10b, which shows an overview of thefunctions of the processing circuit 1015. With reference to FIG. 10b, instep 1050, the processing circuit 1015 obtains a gas concentrationmeasurement value X_(G1). To this end, the processing circuit 1015obtains an analog gas concentration measurement value from the gasconcentration sensor element within the MEMS sensor suite 1025 andconverts the analog flow measurement value to a digital valuerepresentative thereof, X_(G1).

[0174] In step 1055, the processing circuit 1015 provides the gasconcentration measurement value X_(G1) to the first fume hood exhaustmodule 636 via the RF communication circuit 1005.

[0175] In embodiments in which the first fume hood sensor module 640 iscnfigured to obtain gas concentration measurements for a plurality ofdifferent individual gasses, then steps 1050 and 1055 may be repeatedfor each gas.

[0176] The processing circuit 1015 thereafter periodically receivesupdates of its inputs and recalculates the actuator output signal. Inother words, steps 1050 and 1055 are periodically repeated.

[0177]FIGS. 11a and 11 b show the structure and operation of the firstfume hood exhaust module 636. The first fume hood exhaust module 636effectively controls the first fume hood exhaust damper 626 to help ventnoxious gasses present within or in the vicinity of the fume hood 612out of the room 610. The need for venting is based on the concentrationmeasurement value X_(G1) generated by the first fume hood sensor module640, and a gas concentration set point W_(G1).

[0178] It will be appreciated that the second fume hood exhaust module638 has a similar construction and operates in substantially the samemanner as the first fume hood exhaust module 636.

[0179] Referring now specifically to FIG. 11a, the first fume hoodexhaust module 636 has a general construction that is substantiallysimilar to the module 1200 of FIGS. 12a and 12 b. To this end, the firstfume hood exhaust module 636 includes an RF communication circuit 1105,a power management circuit 1110, an processing circuit 1115, an EEPROM1120, and a sensor suite 1125. Each of the elements of the first fumehood exhaust module 636 operates generally as described above inconnection with FIGS. 12a and 12 b.

[0180] The first fume hood exhaust module 636 includes a flow sensingfunctionality, and is further configured to generate an actuator outputsignal. The actuator output signal may suitably be provided on analogoutput pin 1115 a of the processing circuit 1115. The actuator outputsignal is an analog output that controls the operation of the actuatorfor the damper 626. To this end, the analog output pin 1115 a isconnected to an external actuator 1117, which in turn controls theposition of the damper 626.

[0181] To enable the flow sensing functionality, the EEPROM 1120includes configuration information identifying that the processingcircuit 1115 should obtain an air flow measurement information from theMEMS sensor suite 1125. The EEPROM 1120 also includes informationidentifying the tolerable limits for concentration of the gas, or inother words, the gas concentration set point W_(G1) for the gas x beingmeasured in the first fume hood 612. In the exemplary embodimentdescribed herein, the EEPROM 720 further includes sufficient programinstructions or code to carry out the operations illustrated in FIG. 11band described below.

[0182] The RF communication circuit 1105 is preferably configured tocommunicate with the other elements of the subsystem 114 using a localRF communication protocol.

[0183] The operation of the first fume hood exhaust module 636 isdescribed with reference to FIG. 11b, which shows an overview of thefunctions of the processing circuit 1115. With reference to FIG. 11b, instep 1150, the processing circuit 1115 receives from time to time (viathe RF communication circuit 1105) the gas concentration measurementvalue X_(G1), which is provided by the first fume hood sensor module640, as discussed above.

[0184] In step 1155, the processing circuit 1115 calculates a first gasconcentration control output Y_(G1) based on the measured gasconcentration value X_(G1) and the gas concentration set point W_(G1).To this end, the processing circuit 1115 may use an ordinary PIDalgorithm, the configuration of which would be known to those ofordinary skill in the art.

[0185] In step 1160, the processing circuit 1115 then determines a setpoint value for the first fume hood exhaust flow, W_(G1FL), based on thegas concentration control output Y_(G1). To this end, the processingcircuit 1115 may simply set W_(G1FL)=Y_(G1), if scaling or otheradjustments for unit conversion are not required.

[0186] In step 1165, the processing circuit 1115 receives a first fumehood exhaust flow measurement X_(G1FL). To this end, the processingcircuit 1115 obtains an analog flow measurement value from the flowsensor element within the MEMS sensor suite 1125 and converts the analogflow measurement value to a digital value representative thereof,X_(G1FL).

[0187] In step 1170, the processing circuit 1115 calculates a first fumehood exhaust damper control output Y_(G1FL) based on the measured flowX_(G1FL) and the set point value W_(G1FL). Again, the processing circuit1115 may use an ordinary PID algorithm to perform the calculation.

[0188] In step 1175, the processing circuit 1115 provides an actuatoroutput signal corresponding to Y_(G1FL) to its output 1115 a, which inturn provides to the actuator 1117 that causes mechanical adjustment ofthe first fume hood exhaust damper 626.

[0189] As with the processing circuit 715 of FIG. 7a, the processingcircuit 1115 thereafter periodically receives updates of its inputs andrecalculates the actuator output signal. In other words, steps1150-1175, although not necessarily in strict order. The processingcircuit 1115 also communicates the set point W_(G1FL) to the controlmodule 630.

[0190] The above operations of the processing circuit 1115 operate tocontrol the venting of gas-laden air through control of the damper 626.The processing circuit 1115 controls the venting based on the measuredgas concentration X_(G1) received periodically from the first fume hoodsensor module 640 and the desired gas concentration set point W_(G1)stored in the EEPROM 1120. It is noted that the value of W_(G1) may beprogrammed into the EEPROM 1120 upon configuration of the module 636, ormay be received from supervisory devices external to the subsystem 114via the control module 630. It will also be noted, the controlcalculation of step 1155 may be carried out in the first fume hoodsensor module 640.

[0191] One of the advantages of incorporating wireless MEMS modules in abuilding subsystem or system that includes fume hoods is the reducedwiring requirements over normal fume hood systems. Moreover, bydetecting the relative presence of noxious gasses within the fume hood,the fume hood is only vented when noxious gasses are present, or inother words, only as needed. The arrangement thus potentially conservesenergy by ventilating only to the extent necessary. It is noted that thefume hood sensor module 640 and/or the fume hood exhaust module 636 maybe programmed to detect an alarm condition and provide a wireless (orwire output pin) signal to a visible and/or audible alarm device, notshown.

[0192] It will be appreciated that the above described embodiments aremerely illustrative, and that those of ordinary skill in the art mayreadily devise their own adaptations and implementations thatincorporate the principles of the present invention and fall within thespirit and scope thereof. For example, control systems or subsystemshaving any number of fume hoods may be adapted to incorporate theprinciples of the present invention.

[0193] Moreover implementation of the subsystems incorporating featuresfrom either or both of subsystems 110 and 114 may be used in buildingcontrol systems that are not completely wireless. The space controlsubsystems 110 of FIG. 2 may readily be modified for use in aconventional wired building control system. To this end, my copendingapplication, Attorney Docket No. 2002 P 01349 US 01, entitled “BuildingSystem With Reduced Wiring Requirements and Apparatus for Use Therein”,filed on even date herewith and which is incorporated herein byreference, describes a suitable method for incorporating individualsubsystems into current building automation system architecture.

I claim:
 1. An apparatus for use in a building system, the apparatuscomprising: at least one microelectromechanical (MEMs) sensor deviceoperable to generate a process value; a processing circuit operableconvert the process value to an output digital signal configured to becommunicated to another element of a building automation system, thebuilding automation system including one or more devices that areoperable to generate a control output based on set point information andprocess value information from one or more sensors; and wherein the atleast one MEMs sensor device and the processing circuit are integratedonto a first substrate.
 2. The apparatus of claim 1 wherein theprocessing circuit includes a microelectronics A/D converter, themicroelectronics A/D converter operable to receive the process valuefrom the at least one MEMs sensor device and generate digital sensorsignal therefrom.
 3. The apparatus of claim 1 wherein the output digitalsignal is representative of the process value.
 4. The apparatus of claim1 wherein the processing circuit is further operable to generate acontrol output based on the set point information and the process valueinformation from the at least one MEMs sensor device, and wherein theoutput digital signal is representative of the control output.
 5. Theapparatus of claim 1 wherein the at least one MEMs sensor deviceincludes a plurality of MEMs sensor devices.
 6. The apparatus of claim 1further comprising a battery secured to the first substrate.
 7. Theapparatus of claim 1 wherein the first substrate is a semiconductorsubstrate.
 8. The apparatus of claim 6 wherein the battery furthercomprises a lithium ion battery layer.
 9. The apparatus of claim 8further comprising a power management circuit operably coupled to thelithium ion battery layer.
 10. The apparatus of claim 8 furthercomprising a second substrate, and wherein the lithium ion battery layeris disposed between the first substrate and the second substrate. 11.The apparatus of claim 1 further comprising an RF communication circuitoperably coupled to the processing circuit.
 12. The apparatus of claim 1further comprising an EEPROM operably coupled to the processing circuit.13. An arrangement for use in a building system, comprising: a pluralityof sensor modules, each sensor module include at least onemicroelectromechanical (MEMs) sensor device, each sensor module operableto obtain at least one value representative of a measurable quantity ina building; and a plurality of controllers, each controller operablyconnected to receive sensor information representative of at least onevalue obtained by at least one MEMs sensor device, each controllerconfigured to generate a control output based on the sensor informationand set point information, the control output configured to cause anactuator to effect change to the measurable quantity.
 14. Thearrangement of claim 13 wherein at least one of the MEMs sensor devicesand at least one controller is formed on single substrate.
 15. Thearrangement of claim 13 wherein at least one sensor module furthercomprises a plurality of MEMs sensor devices.
 16. The arrangement ofclaim 13 wherein at least one sensor module further comprises amicroelectronics A/D converter, the microelectronics A/D converteroperable to receive the at least ones value from the at least one MEMssensor device and generate digital sensor signal therefrom.
 17. Amethod, comprising: obtaining from a microelectromechanical (MEMs)sensor device at least one value representative of a measurable quantityin a building; generating a control output based on the at least onevalue and set point information, the control output configured to causean actuator to effect change to the measurable quantity.
 18. The methodof claim 17, wherein the set point information includes a desiredtemperature value for at least a portion of the building.
 19. The methodof claim 17, further comprising providing the control control output toan actuator in a building comfort system.
 20. The method of claim 17,further comprising communicating information representative of the atleast one value to a controller using wireless communications, thecontroller operable to generate the control output.